[Libav-user] Loosing Video Frames

[gaurav mishra]

Hi,
I have written some code which opens up a mp4 file , decodes each frame ,
does some manipulation on it and encode it back to new container. Issue i
am seeing here is i am loosing last 3 sec (approx 65 frames) of video .
Below is a simplified version of code which i expected to create a
identical file.which does no manipulation on frame just decode a frame then
encode it back and finally mux it.

while(1) {

        ret = av_read_frame(ifmt_ctx, &packet);
        if(ret < 0) {
            av_log( NULL , AV_LOG_ERROR , "error reading frame or end of
file");
            break;
        }
        AVStream *in_stream = ifmt_ctx->streams[packet.stream_index];
        AVStream *output_stream =
out_stream.format_ctx->streams[packet.stream_index];


            stream_index = packet.stream_index;
            frame_decoded = 0;
            frame = av_frame_alloc();


            ret = avcodec_decode_video2(in_stream->codec, frame,
&frame_decoded, &packet);

            if(ret<0){
                av_frame_free(&frame);
                fprintf(stderr,"could not decode a packet....");
                return ret;
            }

            if(frame_decoded){

                ptsFactor = 2;
                frame->pts = ptsFactor*frameEncodedCount ;
                frameEncodedCount++;

                av_init_packet(&encoded_packet);

                encode_success = 0;

                ret =
avcodec_encode_video2(this->out_stream.format_ctx->streams[0]->codec,
                                            &encoded_packet,
                                            frame,
                                            &encode_success);

                encoded_packet.stream_index = 0;

                if(encode_success){

                    av_packet_rescale_ts(&encoded_packet,

 this->out_stream.format_ctx->streams[0]->codec->time_base,

 this->out_stream.format_ctx->streams[0]->time_base);


                    ret =
av_interleaved_write_frame(this->out_stream.format_ctx, &encoded_packet);
                }
            }


}

I also noticed that the first above code failed to encode first 60 frames
of video. ie
it successfully decoded frames but didnt enter the if(encode_success)
block. Any idea what might be going wrong here.
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